


Pure Sin

by BSplendens



Category: Transformers: Prime
Genre: Dirty Talk, Docking, Dom/sub, Entirely consensual heat fic, Heat Fic, Kinky fun, Oral Sex, Other, Spike sheath fragging, Sticky Sexual Interfacing, Tentacles, Threesome, Very flustered Prime, no but seriously
Language: English
Status: In-Progress
Published: 2016-01-12
Updated: 2016-01-12
Packaged: 2018-05-13 04:39:59
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,889
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5695135
Author URL: https://archiveofourown.org/users/BSplendens/pseuds/BSplendens
Summary: <blockquote class="userstuff">
              <p>Optimus has a bit of a problem with a heat cycle.<br/>Megatron and Soundwave fix that. Mostly by being kinky fraggers and helping Optimus discover a few new kinks of his own.</p>
            </blockquote>





	Pure Sin

**Author's Note:**

> This http://bett-splendens.tumblr.com/post/137004608889/lets-think-about-docking is happening in this fic. Might want to read that post and be sure it won't squick you out.  
> Also some other kinky stuff, hence the title. All entirely consensual despite the heat cycle's influence- prior consent was given and Optimus isn't entirely helpless. He could protest if he wanted to. He just really doesn't want to.

Well.

This is about the hottest thing he's ever seen. 

 

"Isn't he gorgeous?" Megatron whispers, gently caressing the audio fins of the panting mech in his lap. He's leisurely thrusting upwards into a valve that's lovely and tight and oh so  _wet,_ and he's earning the most beautiful moans with every node that he hits. Purring soothingly to Soundwave, he splays a servo over Optimus' inner thigh and pulls the Prime's legs further apart, giving Soundwave a frankly very obscene display. "And he's making just the loveliest noises, but he's trying to stay quiet... would you like to help me coax more sounds from him, hmm? I wonder if we can make him scream for us." he purrs, then grins in a rather predatory fashion as Optimus  _shivers_ at the thought. "I think he likes it when I say things like this, or when I tell him how  _wet_ he's making the berth, or how very tight his valve is." 

 

Optimus' optics are rolled back in his helm already, but he manages to focus his gaze on Soundwave for a moment, panting softly but trying to keep himself together despite the  _filthy_ things being whispered in his audios. "P-please forgive m-my -ah- inco-coherence, I'm- nnh- a b-bit caught up in - _AH-_ a h-heat cycle. I am- nnh- f-fully capable of consent, I p-promise." he pants, then  _moans_ when Megatron  _bites_ at one of his smokestacks. Well. So much for coherence. He's capable of deciding what he likes or doesn't like, but he's not really going to be able to manage much more than positive or negative sounds right now, because Megatron has been  _teasing_ him and is thrusting so  _slowly_ and won't give him what he wants- what he  _needs._

 

Oh. 

Oh Pit. 

Holy frag that's hot. Soundwave's cooling fans kick on and he  _shudders,_ then eagerly slinks over to the berth, though he freezes a short distance away. Wait. Optimus is under the influence of a heat cycle and is currently being spiked... nobody can think in that situation. Is- is this really- 

Is Optimus really able to consent? He'd never suspect Megatron of rape (it goes entirely against his Lord's character), but... but he can't help being suspicious. He... he needs to find out. Slowly slinking up onto the berth, he gently takes Optimus' helm in his servos, forcing the Prime to look at him and searching those brilliant blue optics for any trace of fear or disgust. Nothing but arousal and a bit of a plea, probably for more, but... but this is no guarantee. Biting his lip slightly, the spymaster looks over at Megatron, then glances over when the warlord indicates something on the berthside table. It's a data-pad, and when Soundwave turns it on, he finds something written in a bit of a shaky script. 

_"I am hereby giving my permission for Megatron to do whatever he deems pleasurable for us both, and Soundwave as well should he wish. I am currently fully capable of consenting, and that will not stop. Though I tend to become somewhat incoherent rather quickly, I am still capable of refusing should I decide that I am not enjoying myself._

_Soundwave, Megatron tells me that I am writing this primarily for you. Please feel free to join us, I would love to experience this with you. I must confess, I am rather curious what you can do with your tentacles. May I find out? "_

It's signed, and a very quick check of his archives reveals that the signature matches, though it's a bit shakier than usual- presumably Megatron was being distracting. Well, that's... that's enough for him. And Optimus absolutely seems to be loving this, so he- he'll join. Yes. Nodding slightly, he slowly moves a bit closer, gently pressing himself up against Optimus' front and tracing a servo up the Prime's side. Trilling enquiringly, he eyes Megatron for a moment, then pauses and licks his lips as he sees Optimus looking at him. He- okay, he- 

Optimus' optics are gorgeous and so bright, but Soundwave isn't entirely certain about this mech. Optimus clearly isn't a threat, he's panting and nearly helpless and his spike probably isn't going to pressurize until this heat cycle is over, but- Soundwave really isn't sure about being  _watched_ by him. But he- he does have a plan. Slowly pulling a strip of thick fabric from subspace, he shows it to Optimus, then gently presses it over the larger mech's optics to demonstrate. Is a blindfold okay? 

 

Optimus doesn't resist the blindfold, he just nods a tiny bit, rebooting his voicebox a couple of times and attempting to speak clearly. He doesn't quite manage it, but he does manage an affirmative little panting noise, and he doesn't struggle as Soundwave ties it into place. His optics keep closing anyway, he'll just- just let this- just let Soundwave blindfold him and hope maybe the spymaster will convince Megatron to  _thrust harder._ Whining softly, he tries to thrust himself down onto Megatron's spike, then pants softly and just about begs. "Megatron,  _please-"_ he whispers, then licks his lips and speaks a bit softer, slightly ashamed but really not caring. "H-harder?" 

 

"Shh." Megatron whispers, slipping a servo down to gently rub the Prime's anterior node, then slips a claw up inside the very wet valve. "Soundwave... would you like to join me? I'm certain I can get him stretched open enough for you to fit as well... and I believe he'd enjoy that. Would you like that, Prime? Would you like to have both of us inside you, stretching your pretty little valve open and rubbing over  _every single node_ and overloading you over and over until you're too exhausted to remember anything but how good you feel?" he croons, whispering right in Optimus' audios and then growling when the Prime shudders. "You like this, don't you? Naughty little Prime." 

 

Oh. Oh yes. Soundwave nods, then  _trills_ and extends his tentacles, gently wrapping them around both Optimus and Megatron. Crooning softly, he retracts his spike plating and grinds lightly against Optimus' front to let the blindfolded mech know what he's doing, then leans back to watch Megatron gently stretch the Prime's valve open. Oh, that's lovely... and, despite Megatron's spike being buried in Optimus' valve, there's clearly still a good bit of stretch left. He's just- just going to help that process along, though. Nuzzling gently against the Prime's front, he lightly nips at bright red chassis armor, then slowly trails kisses and nibbles down Optimus' front until he's lapping gently over both the rim of Optimus' valve and the base of Megatron's spike. The heady scent of Optimus' heat is  _very_ strong now, and there's something about the taste of Optimus' lubricant on Megatron's spike that revs his vents more than he ever would have thought possible. Growling, he laps gently at the rim of the Prime's valve, gently easing the panting mech's valve open a bit further to allow Megatron's claws easier access. He'll be gentle, very gentle- has to be gentle. Can't risk hurting Optimus. Good mech, very good mech, and so trusting- can't risk hurting him or making this anywhere near unpleasant. Has to make this good for him. Very good.

 

Optimus moans softly at the additional stretch, his legs splaying even wider, then shudders and  _mewls_ at the sensation of Soundwave licking his valve. And then two of Megatron's fingers are deep in his valve alongside the other mech's spike and he keens in pleasure and his pedes skid against the berth because it  _burns_ but it's so very  _good_ and then the burn eases away and it feels so good but it's not  _enough-_

A pleading little keening sound squirms its way out of his vocalizer and he desperately tries to press down further, trying to get what he  _needs-_ but Megatron's fingers vanish and the Prime whines frantically until he feels Soundwave pressed up against his front and realizes what's about to happen. 

 

Soundwave very carefully positions himself, trilling softly in an attempt to quiet Optimus' unease, then pauses and glances up at Megatron. Only when the warlord nods slightly in affirmation does he thrust, and it's still incredibly slow. Optimus is under a heat cycle, which means his valve will easily stretch open, and no doubt Megatron's gentle thrusts have just about gotten him ready anyway. But  _oh_ Optimus' valve is still very tight around his spike and so very  _hot_ and oh  _Primus_ he's really not going to last long, especially not if Optimus keeps keening in that gorgeous voice. 

 

Optimus gasps softly, back arching, now panting for air and unable to keep any sort of control over his vocalizer. His soft cries of pleasure are getting louder now, wordless keens and moans and whimpers, and he can feel Soundwave's claws tightening briefly on his arms with every sound he makes, so plainly the spymaster likes it- and then a particularly loud moan escapes him and Soundwave  _growls_ and  _slams_ into him and Megatron  _finally_ starts to thrust harder and there goes the last shred of his control. 

 

"Look at you... so desperate, so  _eager,_ and your valve is so incredibly  _tight._ You are gorgeous like this, Optimus, and you feel so  _good..._ and can you hear the sounds you're making? The sounds your  _valve_ is making? You're beyond dripping wet, and if I can hear it then I know Soundwave can hear it and- mmh, no wonder he's starting to thrust harder. Now- relax. You seem so very desperate, and I hate to torment you like this, so-" Megatron purrs, then thrusts up into Optimus' valve,  _hard,_ in time with Soundwave's thrusts- and then his claws dig into the Prime's armor as Optimus  _wails_ and overloads and the Prime's heated valve tightens around his spike. And he can hear Soundwave trilling and feel the spymaster shuddering, so plainly Soundwave just overloaded- most likely from the Prime's cry of pleasure. 

After a moment to regain himself, Megatron very gently pulls out of Optimus' valve, leaning back further against a folded berth pad that he's been using as a cushion and pulling the Prime back as well to sprawl across him. Humming soothingly, he grins up at the spymaster cuddled against Optimus' front, then whispers gently in the panting Prime's audio fins. "Good Prime. Good. Now... relax. You're going to need to cool yourself off a bit, mmm? We aren't anywhere near done with you. I think I'm just going to relax and hold you for a bit, enjoy watching you... I'll just give Soundwave a turn to play with you. Don't worry, he won't tease you like I did... beautiful as you are when you're desperate, he usually likes to just dive right in. He'll usually take some time for foreplay, of course, but... I don't think that'll be needed here, mmm? Your valve is already nicely stretched and oh so very  _wet,_ there's no reason he can't just mount you the second he decides he'd like to. But we might keep you here for just a little while, just to watch you... and maybe to keep you waiting, just a bit. Not enough to let you get uncomfortable, of course, that would be cruel... but I wonder if you might enjoy just a bit of a wait? Let the anticipation build, let you shiver and wait for Soundwave to decide that he's ready to  _take_ you again... I think you'd like that, naughty mech that you are." 

 

Soundwave rumbles drowsily at Optimus, nibbling gently along the first bit of armor that comes near his faceplates (he's removed his visor now that Optimus is blindfolded), then purrs softly and nudges the Prime's legs a bit further apart. Humming softly, he gently strokes a fingertip over the larger mech's swollen valve, then blinks and  _purrs_ as a very  _naughty_ idea comes to him. When a mech is in heat, their spike will usually stay depressurized in order to get any potential partners to focus on their valve. But the nerves are all still online, and... Optimus' spike cover is open. Prurring thoughtfully, he rubs two fingertips very gently over the sensors that surround Optimus' spike housing, then looks up at Megatron and raises an optic ridge in a questioning gesture. Should he-? 

 

"Oh, I do like that idea..." Megatron whispers, then purrs in Optimus' audios, gently petting his (willing) captive's chassis. "You seem to like this, Prime... you like being a naughty mech? You like being pinned between two Decepticons and held still and  _ravished?_ Do you like being able to just let go and stop being so  _good_ and  _proper_ and  _pure?_ Because... if you like that, if you're getting off on how very un-Prime-like this is... I think Soundwave's idea will be very much to your liking. Now... tell me, Optimus, have you ever heard of docking?" he croons, then grins at the startled vent-hitch it earns him. "I'll take that as a yes... but, just to be sure we're talking about the same thing..." 

Megatron's servo trails down Optimus' front until he's rubbing firmly at the rim of the Prime's spike housing, his fingertips dipping inside just slightly to make Optimus gasp again. "I won't be trying that with you, of course... that would take a lot of specialized preparation. Perhaps something for later. For now, though... there's no reason Soundwave can't spike you right now, unless you don't like the idea. Right now, your frame will respond positively to just about anything, so I'm going to ask you now while you're still coherent. What do you think of that idea? Do you want to try? We can stop if you don't like it, but... you're such a kinky little mech, I think you'll enjoy this." 

 

_Oh Primus._

_Oh dear Primus._

Optimus blushes very brightly indeed, then licks his lips and slowly twitches his hips up against Megatron's fingertips, processing how that feels. It's- Pit, it's  _filthy_ and it's so incredibly improper and he  _loves_ the thought even as it makes him blush all the way up to his audials. He's- he's never tried this, but- he's always considered it, wondered how it might feel, and- and he- and Megatron is brushing his fingertips carefully into his spike sheath and he never would have thought to do this but it's so  _good-_

Licking his lips, Optimus nods slightly, then inhales deeply and tries to calm himself. "I- I t-think I w-would l-like to try, but- one condition. I- I would r-really rather n-not h-have m-my optics -nnh- covered." he manages, though he doesn't raise a servo to take the blindfold off- he's not sure that he can. He's still quite shaky. 

 

Hmm. He'd rather not be looked at, but Optimus is going to become extremely incoherent very soon, and most likely the Prime either won't be looking at him or won't care. Soundwave tilts his helm slightly, considering it, then reaches up and gently tugs the blindfold away. Licking his lips hungrily, he meets Optimus' (dazed) gaze for a moment, then pushes the Prime's legs apart and licks firmly over the larger mech's spike housing. He doesn't normally like to use his mouth on another's spike, but he'll make an exception here. Partly so he can hear Optimus moan in that gorgeous voice. And he's not disappointed- such a lovely sound. Thrumming in approval, he laps gently at the sensors around Optimus' spike channel, then presses a bit deeper. He's not entirely certain what he's doing, he's never tried something like this, but... the principle should be something like with a valve, yes? Different taste, different texture, similar aim. So he tries what he knows, and he earns himself the most beautiful sounds of pleasure, and when he rolls his optics up to look at Optimus- well, the Prime isn't looking at him. 

 

Optimus is whimpering softly, helm lolling to the side under the onslaught of entirely unfamiliar pleasure, unable to meet Soundwave's optics and still blushing so very brightly. This feels good, and it's so  _filthy_ and he really ought to be embarrassed but it feels so  _good_ so very good and he can't help being flustered but  _he doesn't care_ and Megatron is crooning filthy things in his audials and  _oh Primus-_

 

"You like that? Naughty little Prime... I thought you would. Imagine if your Autobots could see you now... the leader of the Decepticons petting you and holding you still so that the notorious Decepticon spymaster can lick out your spike sheath and get you ready to try _docking_ for the first time. How... scandalous. How improper of you. How _lovely._ Do you have any idea how brightly you're blushing? You are gorgeous. Now... enjoy yourself. I can't wait to see how you react when Soundwave actually spikes you... this is just something a bit unusual, but  _that?_ Mmm... if you're getting off on just being a little bit naughty,  this is going to make you overload so hard you'll have to reboot your processor." he purrs, then slips a servo down and tightly grips the back of Optimus' knee, hiking his leg up and putting his hips at a nice angle. "Here you are, Soundwave... our little Prime is ready for you. And... might I suggest that you show him what you can do with those tentacles?" 

 

Soundwave wraps his tentacles gently around Optimus' thighs and rubs one gently over the Prime's valve, watching his face for a reaction, then purrs and gently runs his tendrils around the rim of the Prime's heated valve. Humming soothingly, he slowly slips all of the tendrils up into the big mech's valve, then shifts and penetrates Optimus' valve in one smooth push. Relishing the croon of pleasure it earns him, he gently manipulates the small tendrils until he finds a few nodes, then wraps the delicate tendril-tips around them and squeezes. He's learned what to do with his tentacles to make his partner feel good, spike or valve, and Optimus is so very worked up that it's not much trouble. 

Slinking up Optimus' front, Soundwave settles between the Prime's spread thighs, boldly meeting his optics for just a moment before he gently presses the head of his spike into Optimus' spike sheath. Waiting just a moment to give the Prime a chance at refusal, he rocks very gently against the first set of calipers, then croons and slowly thrusts a bit deeper. He moves slowly and gently at first, doing his best to mimic what Megatron did the first time he felt safe enough to be spiked by his Lord, mostly in an attempt to not upset or hurt Optimus. It's not likely, but he wants to make this good, and so he moves gently until he can feel Optimus' spike against his. At that point, he pauses again, one tentacle still gently thrusting and twisting in Optimus' valve. He wants to be sure that this is good for the Prime... though, judging by those soft whimpers and moans, this is very good. 

 

Nearly overwhelmed by the two very new sensations and the all-encompassing realization of just how  _forbidden_ this is and the things that Megatron is saying to him, the Prime just pants helplessly, caught between Megatron and Soundwave and unable to do anything other than moan and whimper and enjoy himself- and overload. Megatron whispers something in Cybertronian, a suggestion of how his team might react to seeing him like this, and that combines with a particularly nice twist of Soundwave's tentacle in his valve and a soft little thrust to send him right over the edge- and the very second he starts to regain himself, Soundwave is moving, thrusting firmly into him, into his- 

_Oh Primus-_

 

 

He loses track of himself after awhile. At least two more overloads later, he's sprawled strutless against Megatron's front, whining softly and trying to process how he feels about the sensation of Soundwave's transfluid filling his spike sheath. He... he's pretty sure he likes this. It's so very odd, but he likes it. 

He's starting to get tired, though, and he'd- he'd like a break. Giving an uncomfortable little sound, he squirms slightly under Soundwave's touches, then clumsily grabs at the spymaster's back armor and keeps him from retreating. No, no, he doesn't want Soundwave to back up- he just wants to take a break from being fragged into the berth and/or into Megatron's plating. The heat cycle isn't going to let him rest easy for awhile, anyway, so he just needs to relax and try to regain his strength.

A cube of energon is pressed gently to his lips and he gulps hungrily at it, tired and thirsty and eager to regain his energy so that they can keep going. This feels good, very good, and it's  _sinful_ but it's so  _good_ and it's a far better way to spend a heat cycle than just locking himself in his quarters and stuffing a toy up his own valve. As soon as he's no longer tired, he absolutely wants to keep going. Megatron definitely seems eager enough to continue, and though Soundwave is sprawled sleepily across his front, the spymaster is still petting lightly at his seams and wrapping those tentacles gently around various parts of him. Apparently they both have no problems with continuing. 

And he can still feel the  _heat_ coming off of his own faceplates, the heat of a blush that's just about covered his entire face. He's flustered, very flustered- maybe not quite embarrassed, but close. He's not entirely sure why, but he- he actually likes this feeling, likes this heat in his faceplates and the sensation that maybe he's doing something forbidden but he doesn't  _care._ And Megatron is saying these  _things_ to him, these naughty things in such a dominant voice that he- he can't help but- 

 

"Drink up, Optimus... you'll need your strength." Megatron purrs, then grins as Optimus raises a shaky servo and tries to grip the cube. "You're already a bit wrecked... can't wait to see what sort of shape you'll be in after another few overloads. I fully intend to overload you into the next century, Prime, and I'm certainly not going to stop until you're even more strutless than this. We can take a break for now, of course, but... we'll keep going. Rest up... you'll need it. Maybe we can try a few new things, hmm? Since you liked that so much." he croons, then chuckles softly as Optimus whines and covers his face with his servos. "Look at him, Soundwave. Isn't he adorable? He's blushing so much... so very flustered. You'd think we'd just taken his seals. Or, hmm... in a way, I suppose we did. We tried something very new, didn't we, Prime? And you  _loved_ it." 

 

That blush is just about permanent at this point, isn't it? Soundwave blinks, then chuckles softly and nuzzles up against Optimus' chassis before inching up enough to nibble at the Prime's throat cables. He's rather tired at the moment, but  _mmm,_ he is absolutely still enjoying himself. Maybe he'll just... just sit here and watch, maybe wrap his tentacles around the Prime's thighs and coax his legs open further and let Megatron do many, many naughty things to him.

Optimus definitely has no objections. 

**Author's Note:**

> More incoming at some point.


End file.
